A kind of electronic-controlled installation that is used for residual current protecting
The present invention relates to a kind of electronic-controlled installation that is used for residual current protecting, belong to the low-voltage distribution protective device.
Present Aftercurrent protecting equipment; the patent No. of application was 94214193.8 as on June 14th, 1994; the patent No. that name is called " RCD " and application on December 11st, 1996 is 96239347.9; name is called " intelligent centralized-control type aftercurrent action protecting equipment "; all can not satisfy when the three-phase circuit phase failure and still can carry out the requirement of residual current protecting; Electro Magnetic Compatibility is not high, thereby has influenced the use of this product at aspects such as fail safe, reliabilities.
The purpose of this invention is to provide a kind of electronic-controlled installation that is used for residual current protecting, can reach set point time-division deenergizing at three-phase circuit (with or without neutral line N, down together) residual current; Still can reliably working when the three-phase circuit generation phase failure, and Electro Magnetic Compatibility is good.
A kind of electronic-controlled installation that is used for residual current protecting, it comprises rectification circuit, provides voltage stabilizing circuit and thyristor gating circuit direct voltage through tripping coil; Voltage stabilizing circuit produces stable low-voltage dc power supply, and is used for testing circuit; Testing circuit amplifies, relatively waits processing the detected signal of zero sequence current mutual inductor, and sends the relative trigger pulse signal to thyristor gating circuit; Thyristor gating circuit, the start pulse signal by testing circuit is sent triggers by secondary, makes the conducting of dropout loop, thereby makes the trip gear action and the disjunction three-phase circuit; Simulation experiment circuit, when pressing test button, the test winding of zero sequence current mutual inductor is connected the back and produces electric current with the current-limiting circuit of rectification circuit, measure in the winding and just induce electric current, just send start pulse signal after testing circuit detects, make the conducting of dropout loop.
The electronic-controlled installation that is used for residual current acting of the present invention can reach set point time-division deenergizing at the three-phase circuit residual current.This control device still can obtain working power from other two-phase in that three-phase circuit is arbitrary when mutually the phase failure taking place, and when the residual current that detects this two-phase reached set point, promptly the disjunction three-phase circuit carried out reliable residual current protecting, and Electro Magnetic Compatibility is good.
Below in conjunction with accompanying drawing the present invention is further described below.
Fig. 1 is the theory diagram of invention.
Fig. 2 is the rectification circuit and the simulation experiment circuit of invention.
Fig. 3 is the voltage stabilizing circuit of invention.
Fig. 4 is the testing circuit of invention.
Fig. 5 is the thyristor gating circuit of invention.
Referring to Fig. 2, rectification circuit is made up of current-limiting circuit, overvoltage crowbar, three-phase bridge rectifier circuit; Current-limiting circuit connects three-phase bridge rectifier circuit and overvoltage crowbar.Three-phase power line was connected to the current-limiting circuit of being made up of resistance R 101-R103 before passing zero sequence current mutual inductor; deliver to the overvoltage crowbar of forming by piezo-resistance RV101-RV103 then; with the high pressure disturbance voltage that suppresses to introduce by the three phase mains end; deliver to the three-phase bridge rectifier circuit of being made up of diode VD102-107 simultaneously and carry out rectification, the direct voltage of rectification output is delivered to voltage stabilizing circuit and thyristor gating circuit behind tripping coil.The negative peak high pressure that the tripping coil two ends formed when diode VD101 was used to prevent the switch dropout.
Simulation experiment circuit is made up of test winding, the test button of test resistance, zero sequence current mutual inductor; Test resistance connects test button, and test button connects the test winding of zero sequence current mutual inductor.Test winding one end of zero sequence current mutual inductor is connected to the C phase behind current-limiting resistance R103, another termination test button AN201, and test button AN201 connects with test resistance R201 again, after be connected to the A phase behind the current-limiting resistance R101.When pressing test button AN201, the test winding of zero sequence current mutual inductor produces electric current, measures in the winding and just induces electric current, just sends start pulse signal after testing circuit detects, and makes the conducting of dropout loop.
Referring to Fig. 3; voltage stabilizing circuit is made up of step-down current-limiting circuit, overvoltage crowbar, three grades of capacitance-resistance bleeder circuits, three grades of serial regulating circuits; the step-down current-limiting circuit connects overvoltage crowbar and three grades of capacitance-resistance bleeder circuits, and three grades of capacitance-resistance bleeder circuits connect three grades of serial regulating circuits.The direct voltage of being sent here by rectification circuit is connected to the transient voltage suppressor FV301 that is used for overvoltage protection after resistance R 301 step-down current limlitings; suppress the spike disturbance voltage; be connected to simultaneously by capacitor C 301-C303; three grades of capacitance-resistance bleeder circuits that resistance R 302-R304 forms; three grades of capacitance-resistance bleeder circuits will be after step-down after-applied at different levels in three grades of serial regulating circuits of the balanced dividing potential drop of direct voltage; wherein three terminal regulator V301 is to resistance R 302; capacitor C 301 gained dividing potential drops are carried out voltage stabilizing; voltage stabilizing output and resistance R 303; send into three terminal regulator V302 after capacitor C 302 gained dividing potential drops superpose again and carry out voltage stabilizing; voltage stabilizing output and resistance R 304; send into three terminal regulator V303 after capacitor C 303 gained dividing potential drops superpose again and carry out voltage stabilizing; the voltage stabilizing output of three terminal regulator V303 is through transient voltage suppressor FV302 overvoltage protection; after capacitor C 304 filtering; again through resistance R 305 step-downs; be a stabilizing low voltage DC power supply after capacitor C 305 filtering, for the usefulness of testing circuit.
Referring to Fig. 4; in testing circuit; by capacitor C 401; C402; resistance R 401-R402; R405; diode combination VD401 forms input signal channel; the signal of being sent here by zero sequence current mutual inductor measurement winding is carried out the current/voltage conversion; overvoltage protection; anti-interference is handled; wherein resistance R 401 is used for the current/voltage conversion; resistance R 402; diode combination VD401 is used for overvoltage protection; capacitor C 401; C402 is used for anti-interference to be handled; signal is after treatment sent into integrated circuit (IC) 401 and is amplified; IC401 is KC126; resistance R 403-R406; capacitor C 403-C407 is the periphery biasing of amplifying circuit, and the signal after the amplification is sent into the testing circuit of integrated circuit (IC) 401 inside with reference voltage.Resistance R 407 is the peripheral biasing resistor of integrated circuit (IC) 401 inner constant-current sources, is used to produce the DC power supply that inner testing circuit is used, and C408-C409 is a filter capacitor, and C410-C414 is an anti-interference electric capacity.When residual current reaches set point, send start pulse signal by 8 pin of integrated circuit (IC) 401.
Referring to Fig. 5, thyristor gating circuit is made up of one-level thyristor gating circuit, overvoltage crowbar, secondary thyristor gating circuit, and the one-level thyristor gating circuit connects overvoltage crowbar and secondary thyristor gating circuit.The one-level thyristor gating circuit is made up of controllable silicon VT501, resistance R 501-R502, capacitor C 501, and connects the overvoltage crowbar that transient voltage suppressor FV501 forms, and connects the secondary thyristor gating circuit that secondary controllable silicon VT502 forms simultaneously.C501 is an anti-interference electric capacity.Transient voltage suppressor FV501 is used to prevent because of making controllable silicon VT501 triggering and conducting cause misoperation behind the spike harassing and wrecking pulse breakdown controllable silicon VT502.When testing circuit sends trigger impulse, at first conducting of controllable silicon VT502, its conducting electric current converts voltage signal and dividing potential drop to by R501-R502, on resistance R 502, form a direct current voltage, make controllable silicon VT501 conducting thereupon, form the dropout loop by tripping coil, thereby make trip gear action, disjunction three-phase circuit.